I agree with USMCMOM in that you should get a second opinion. I had a 16mm Colloid cyst diagnosed in July 2008 that caused significant hydrocephalus. I had various neurologic symptoms including fatigue, short term memory deficits
and unsteady walking. The neurosurgeons I saw recommended a VP shunt to treat the hydrocephalus because it is a less invasive procedure that removing the cyst. Cyst removal can cause permanent damage to the fornix in the brain and loss of short term memory. I chose to follow their advice and now have a VP shunt and still have the cyst in my third ventricle. I saw dramatic improvement of my symptoms two weeks following the surgery, and by six weeks I felt fully recovered. I know that I am dependent upon the shunt to control the hydrocephalus, but I am grateful to have recovered all my brain function and have an intact short term memory. I feel that I made the best decision to treat my condition. Good luck with your decision to treat your colloid cyst.